Confidential Communication in the Internet

Course
  • Cybersecurity

Confidential Communication in the Internet

A message on the Internet is sent through several networks and via different stations on its way to the target system. The individual stations are responsible for ensuring that the message is properly forwarded and finally delivered to the correct recipient. Each of these stations, if the message is sent in plain text, can receive the message and read its content. This means that a potential attacker, if he controls one of these intermediate systems, can also read the content of the message and even modify it before retransmitting it. Such attacks can have extreme effects on communication.

In this course we will look at how and whether your connection to online banking is secure or whether the content of an e-mail is trustworthy. For this purpose we will deal with the basics of cryptography, security objectives and different types of encryption. In addition, we will provide insights into different models and standards that are used in practice.

Offered by Prof. Dr. Christoph Meinel | Last updated on Sep 17, 2026 | 7219 enrollments

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  • Beginner
  • EN
  • Certificate
Course information

A message on the Internet is sent through several networks and via different stations on its way to the target system. The individual stations are responsible for ensuring that the message is properly forwarded and finally delivered to the correct recipient. Each of these stations, if the message is sent in plain text, can receive the message and read its content. This means that a potential attacker, if he controls one of these intermediate systems, can also read the content of the message and even modify it before retransmitting it. Such attacks can have an extreme impact on communication, as information is no longer confidential and the credibility of the message can no longer be established.

For this reason, encryption procedures are used to ensure that the content of messages can only be interpreted by the sender and the recipient. This ensures that the information remains confidential. Furthermore, there are procedures that can be used to detect whether there has been a change in the information in a message. These security procedures are currently in widespread use and are used in particular for sensitive services such as online banking.

In this course we will look at how and whether your connection to online banking is secure or whether the content of an e-mail is trustworthy.
For this we will deal with the basics of cryptography, security objectives and different types of encryption. In addition, we will provide insights into different models and standards that are used in practice.

Take the cybersecurity exam and get a qualified certificate!

This course content is part of the cybersecurity series on openHPI. The series consists of three courses and ends with the Cybersecurity exam in September 2022. By the Cybersecurity exam, you have the chance to receive a free record of achievement or a qualified certificate. Therefore, please attend the three courses Confidential Communication in the Internet, Digital Identities, and Cyberthreats by Malware and finish them with a confirmation of participation. This allows you to register for the cybersecurity exam which covers questions from all three courses.

Contents:

  • Introduction
  • Safety objectives
  • Cryptography
  • Cryptoprotocols & Attacks
  • Certificates and Trust Center
  • Encryption
  • Signatures
  • Technical digressions (AES, hash functions, ...)

Key data on the course

  • Required skills: general IT knowledge, solid mathematical knowledge
  • Course level: Basics, but courses also go into depth
  • Target group: Everyone interested in encryption methods and digital signatures
  • Effort: 3-6 hours per course week (optional: 2 hours for the Cybersecurity Basics - Exam)

Follow us on Twitter: @openHPI. For tweets about this course please use the hashtag #confidentialcommunication2022

Visit us on Facebook: https://www.facebook.com/OpenHPI

More video lectures can be found at www.tele-task.de.

Attention: This course is currently in self-study mode, in which you do not have access to graded assignments/exams. Therefore, we can only issue you a certificate of participation.

Requirements for Proofs of Achievement
  • Confirmation of Participation: You will automatically receive a free Confirmation of Participation once you have completed at least 80% of the content.
  • Certificate: You will receive your official openHPI Certificate by earning at least 50% of the maximum number of points from all graded assignments.

Find out more on our page for Proofs of Achievement and Guidelines.

Our teachers

Prof. Dr. Christoph Meinel

Christoph Meinel (Univ.-Prof., Dr.rer.nat., Dr.sc.nat., 1954) was Managing and Scientific Director of the Hasso Plattner Institute for Digital Engineering gGmbH (HPI) until March 2023. He is a full professor (C4) for Informatics at the university of Potsdam and has the chair for "Internet Technology and Systems" at the HPI. From 2017 to 2021 he was the founding dean of the Digital Engineering Faculty of the University of Potsdam. Now he is president of the German University of Digital Science, the first digital university in Germany.
His research interests are broadly diversified in the area of innovative Internet applications and systems, especially in digital education, e-learning & tele-teaching, artifical intelligence and deep learing, and Internet and information security. He is also active in the field of innovation research and investigates the Stanford innovation method design thinking. Former research interest were in telemedicine, as well as in the theoretical foundations of computer science in the areas of complexity theory and efficient OBDD-based algorithms and data structures.